To counter all the negative responses: I'm a PC tech (over 15 years experience) and one of the most common problems I hear from my clients is their computer is slow and the most common cause of this (besides a virus or malware) is software adding itself, usually without the user's knowledge, to the computer's startup. All these programs then start when you begin a Windows session, slowing not only boot-up time, but your computer as a whole. Most of them don't need to be in startup, the obvious exceptions are antivirus and firewalls.

To see what programs are starting with your computer go to Start, Run and type in msconfig, click ok, or hit enter, then click on the startup tab in the system configuration window. I bet you'll be surprised with all the programs that are running in the background!

Zard's Startup Defender sits quietly in your taskbar and alerts you when software tries to add itself to your startup, then lets you allow or deny adding it. This is one of the most useful programs you can have on your computer.

WinPatrol is far better, even the free version. If you want the Plus version, it's $29.95. Don't mess with success, just get WinPatrol. You'll be glad you did.

http://www.winpatrol.com/

Not just the same but free and very useful for me since years:
TeaTimer which comes with Spybot-Search&Destroy:
http://www.safer-networking.org/en/faq/33.html
"The Resident TeaTimer is a tool of Spybot-S&D which perpetually monitors the processes called/initiated. It immediately detects known malicious processes wanting to start and terminates them giving you some options, how to deal with this process in the future. You can set TeaTimer to:
be informed, when the process tries to start again
automatically kill the process
or generally allow the process to run
There is also an option to delete the file associated with this process.
In addition, TeaTimer detects when something wants to change some critical registry keys. TeaTimer can protect you against such changes again giving you an option: You can either Allow or Deny the change.
The TeaTimer is always running in the background.

If you miss this, here's an alternative that does the same.
Free. Quick Startup by Glarysoft

@ 10 JDepp

Spam? Are you kidding? How can it be spam when you have to make a deliberate, conscious decision to come visit this website? It's not like GOTD is emailing the program directly to your inbox without permission.